NASA scientists working with Curiosity have announced that water did indeed flow on Mars at one point in its history — and we're not talking trickles. A newly discovered ancient streambed indicates that the water ran fast and deep, possibly as much as hip deep. The discovery marks a precedent setting achievement for the lander, one that will add serious credibility to the suggestion that Mars was once capable of harboring life.

Satellite-based images had suggested that rivers once flowed on Mars, but this discovery offers near-definitive proof that water was once a major geological fixture of the Red Planet.

Remnants of the now dried-up stream were found inside the Gale Crater within which Curiosity is working. Proof of running water came in the form of rounded pebbles and gravel fragments that could have only been weathered by strong currents. Their shape and orientation suggests long-distance transport from above the rim of the crater, where a channel named Peace Vallis feeds into the alluvial fan. And because there are many channels like this, the NASA scientists believe the flows were continuous or repeated for long durations, and not just once or twice for a few years.

"From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep," noted Curiosity scientist William Dietrich speaking through NASA's official release. "Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we're actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it."

But Curiosity's work on the streambed won't stop there. The robotic geologist is scheduled to conduct a chemical analysis of the rocks to determine its elemental composition. It's hoped that the analysis will reveal more characteristics of the previously wet environment that formed these deposits.

And in addition to that, Curiosity will continue to make its way to the slope of Mount Sharp, where it's expected to study clay and sulfate minerals — deposits that may be good preservers of carbon-based organic chemicals that are potential ingredients for life.

But now, given that a river once flowed through the area, Curiosity's ongoing mission to search for signs of previous habitability has suddenly become all the more promising.